1. Field of the Invention
The present invention relates generally to modular outer space structures, and more specifically to a lightweight modular structure that is capable of rapid assembly, airtight pressurization, and utilization for habitation on the surface of celestial bodies such as the Moon and Mars. This invention is capable of either robotic or human assembly.
2. Description of the Prior Art
Historically assembly of structures in outer space has been a long, tedious, labor-intensive and expensive process, as demonstrated the International Space Station assembly process. Due to the many hours of arduous and complex activity necessary to assemble space structures in a vacuum, astronauts have faced a significant risk of accidental injury or death during assembly activities, particularly if their protective space suit is damaged.
Inexpensive, lightweight and portable structures' most significant period of development began in 1941 when the U.S. Government believed war was imminent and the U.S. military saw a need for lightweight portable structures. The government asked the George A. Fuller Company to design and produce a but to US specification. These huts became known as “Quonset huts”, and approximately 165,000 of the various versions of the design were built and sold to the U.S. government during World War II. (http://www.seabeesmuseum.com/Quonset_Huts.html)
In the years since World War II many designs for rapid assembly, lightweight, portable structures have been patented. Some examples are U.S Pat. No. 6,594,958 to Melson et al., U.S Pat. No. 6,131,343 to Jackson, Jr., U.S Pat. No. 5,581,960 to Lewis, U.S Pat. No. 5,333,421 to McKenna, U.S Pat. No. 4,887,397 to Peterson, and U.S Pat. No. 4,469,676 to Davey. These structures were not designed for rocket launching and use in outer space. These structures were not designed to fit in the payload faring of a launch vehicle when unassembled. These structures are not airtight, cannot be pressurized, and cannot be equipped with life support systems for use in outer space. These structures are not thermally insulated to maintain an interior temperature range in which humans can survive when temperatures exterior to the structure are in the extreme range encountered in outer space. These structures do not provide occupants with any significant protection against solar/solar flare proton radiation and galactic cosmic radiation.
U.S. Pat. No. 5,086,999 to Mullen is an example of a rigid modular structure designed for use in outer space. This invention is composed primarily of metal, so its weight makes it expensive to launch, and it is not designed for use on the surface of celestial bodies. This invention is designed to be transported in the cargo bay of a United States space shuttle. The United States no longer operates the space shuttle, so this invention is obsolete.
In recent years, U.S. company Bigelow Aerospace, LLC has demonstrated inflatable space structures with soft-shell exteriors made of generally pliable and flexible material. These structures do not require human assembly; they launch deflated and inflate after they reach orbit. Two separately-launched Bigelow inflatable modules are currently in low Earth orbit that did not require human assembly.
As currently conceived, inflatable structures cannot accommodate entry of large articles into the structure without significant modification and human assembly activity, they do not provide any significant protection against solar/solar flare proton radiation or galactic cosmic radiation (gamma rays), and they are not designed to bear external weight, as for example a structure might experience if it were buried under 1-2 meters of extraterrestrial material. Modular inflatable and expandable space structures are typified, for example, by U.S. Pat. No. 6,899,301 B2 to Bigelow, U.S. Pat. No. 6,439,508 to Taylor, U.S. Pat. No. 6,231,010 to Schneider, et al, U.S. Pat. No. 6,547,189 to Raboin, et al, and U.S. Pat. No. 5,086,999 to Mullen.
U.S. Pat. No. 7,469,864 to Bigelow describes a method of assembling a habitable structure comprised of a plurality of inflatable structures, connecting nodes, busses, and landing pads that are assembled in orbit, and subsequently landed on the surface of an extraterrestrial mass. This structure can be assembled robotically. This design risks structural deformation and degradation of structural integrity during the assembled structure's descent to the surface. The structure provides no significant radiation shielding, and is not designed for the external load that would result if the structure were buried under two meters of extraterrestrial material.
U.S. Pat. No. 6,899,301 to Bigelow describes a method for installing windows on an inflatable structure. This method requires activity outside of the structure to locate a bladder and template on the outer shell, to penetrate and cut the fabric of the outer shell following the template, and to install the window. This patent does not state that the method can be accomplished robotically, so human activity must be necessary. It follows that installation of hangar doors would require human assembly efforts outside the structure as well. Thus, this design poses a risk of injury or death of astronauts when astronauts work in the vacuum outside the facility to perform assembly work. This structural design can also take a significant amount of time to completely assemble if the structure were to include hangar doors and/or one or more windows.
U.S. Pat. No. 8,621,822 to Brockwell describes structural members formed from strips of material with notches on the strips, wound with woven tensile material in the notches. When at least one pair of structural members are joined together, the woven patterns of tensile material distribute stress throughout the structure. Total catastrophic failures in composite materials are substantially avoided, and the strength-to-weight ratio of structures can be increased through use of this technology.